stellar

Improve Zobrist lookup tables

4 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/ CMakeLists.txt b/ CMakeLists.txt

@@ -3,7 +3,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON) project( Stellar

VERSION 1.3.5

VERSION 1.3.6

DESCRIPTION "Chess engine written in C++" HOMEPAGE_URL https://git.dimitrijedobrota.com/stellar.git LANGUAGES CXX

diff --git a/ src/board/board.cpp b/ src/board/board.cpp

@@ -8,10 +8,14 @@ #include "utils_ui.hpp" #include "zobrist.hpp"

namespace zobrist {

/* Init arrays for Zobris hashing */

std::array<std::array<U64, 64>, 12> zobrist::keys_piece = {{{0}}};

std::array<U64, 64> zobrist::keys_enpassant = {{0}};

std::array<U64, 16> zobrist::keys_castle = {{0}};

U64 keys_piece[2][12][64] = {0};

U64 keys_enpassant[64] = {0};

U64 keys_castle[16] = {0};

} // namespace zobrist

/* Getters */

diff --git a/ src/board/board.hpp b/ src/board/board.hpp

@@ -197,13 +197,11 @@ U64 zobrist::hash(const Board &board) { uint8_t square = 0; for (Type type = PAWN; type <= KING; ++type) {

int piece_white_index = piece::get_index(type, WHITE);

U64 bitboard_white = board.get_bitboard_piece(type, WHITE);

bitboard_for_each_bit(square, bitboard_white) { key_final ^= keys_piece[piece_white_index][square]; }

bitboard_for_each_bit(square, bitboard_white) { key_final ^= keys_piece[WHITE][type][square]; }

int piece_black_index = piece::get_index(type, BLACK);

U64 bitboard_black = board.get_bitboard_piece(type, BLACK);

bitboard_for_each_bit(square, bitboard_black) { key_final ^= keys_piece[piece_black_index][square]; }

bitboard_for_each_bit(square, bitboard_black) { key_final ^= keys_piece[BLACK][type][square]; }

} key_final ^= keys_castle[board.get_castle()];

diff --git a/ src/board/zobrist.hpp b/ src/board/zobrist.hpp

@@ -11,20 +11,18 @@ class Board; namespace zobrist {

extern std::array<std::array<U64, 64>, 12> keys_piece;

extern std::array<U64, 64> keys_enpassant;

extern std::array<U64, 16> keys_castle;

extern U64 keys_piece[2][12][64];

extern U64 keys_enpassant[64];

extern U64 keys_castle[16];

const U64 keys_side = Random(C32(1699391443))(); inline void init() { Random gen1(C64(1804289383)); for (Type type = PAWN; type <= KING; ++type) {

int piece_index_white = piece::get(type, Color::WHITE).index;

int piece_index_black = piece::get(type, Color::BLACK).index;

for (int square = 0; square < 64; square++) {

keys_piece[piece_index_white][square] = gen1();

keys_piece[piece_index_black][square] = gen1();

keys_piece[WHITE][type][square] = gen1();

keys_piece[BLACK][type][square] = gen1();

} }

@@ -44,7 +42,7 @@ inline constexpr U64 key_side() { return keys_side; } inline constexpr U64 key_castle(int exp) { return keys_castle[exp]; } inline constexpr U64 key_enpassant(Square square) { return keys_enpassant[square]; } inline constexpr U64 key_piece(Type type, Color color, Square square) {

return keys_piece[piece::get_index(type, color)][square];

return keys_piece[color][type][square];

} }; // namespace zobrist